Century Rain is not a part of Revelation Space universe (AR himself calls it Inhibitors universe). My favorite book is Chasm City -- in fact I think that of entire Inhibitors series it should be read first. Revelation Space is very dense, and as first exposure to Reynolds might put some people off.

Absolution Gap (the last book in the series) started out great, but the ending was rushed and unsatisfactory. Also, toward the end of the series the science part gets rather rubbery.

I read Pushing Ice (good, not spectacular), and all of the Inhibitors series except the latest book, which was not yet released in the US.

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Fiction has to be plausible. Reality is under no such constraint.